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V4L/DVB: ov7670: Don't use SMBUS I/O 

Contrary to my earlier belief, the ov7670 is not actually an SMBUS device,
though it will pretend to be one if it's in a good mood.  Unfortunately,
it's rarely in a good mood, especially on the XO 1.5.  So use low-level i2c
I/O instead.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
Jonathan Corbet 2010-02-28 21:02:55 -03:00 committed by Mauro Carvalho Chehab
parent d8d201552f
commit 2bf7de4888
1 changed files with 30 additions and 4 deletions
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34
drivers/media/video/ov7670.c
View File

@ -410,16 +410,33 @@ static struct regval_list ov7670_fmt_raw[] = {
/*
* Low-level register I/O.
*/
static int ov7670_read(struct v4l2_subdev *sd, unsigned char reg,
unsigned char *value)
{
struct i2c_client *client = v4l2_get_subdevdata(sd);
u8 data = reg;
struct i2c_msg msg;
int ret;
ret = i2c_smbus_read_byte_data(client, reg);
/*
* Send out the register address...
*/
msg.addr = client->addr;
msg.flags = 0;
msg.len = 1;
msg.buf = &data;
ret = i2c_transfer(client->adapter, &msg, 1);
if (ret < 0) {
printk(KERN_ERR "Error %d on register write\n", ret);
return ret;
}
/*
* ...then read back the result.
*/
msg.flags = I2C_M_RD;
ret = i2c_transfer(client->adapter, &msg, 1);
if (ret >= 0) {
*value = (unsigned char)ret;
*value = data;
ret = 0;
}
return ret;
@ -430,8 +447,17 @@ static int ov7670_write(struct v4l2_subdev *sd, unsigned char reg,
unsigned char value)
{
struct i2c_client *client = v4l2_get_subdevdata(sd);
int ret = i2c_smbus_write_byte_data(client, reg, value);
struct i2c_msg msg;
unsigned char data[2] = { reg, value };
int ret;
msg.addr = client->addr;
msg.flags = 0;
msg.len = 2;
msg.buf = data;
ret = i2c_transfer(client->adapter, &msg, 1);
if (ret > 0)
ret = 0;
if (reg == REG_COM7 && (value & COM7_RESET))
msleep(5); /* Wait for reset to run */
return ret;